Unberreamer



F. J. FOX.

UNDERREAMER.

APPLICATION FILED APR.21,1916.

Patented Aug. 1, 1916.

2 SHEETS-SHEET 1.

F. J. FOX.

UNDEBREAMER.

APPLICATION FILED APR-21,1916.

Patented Aug. 1, 1916.

2 SHEETS-SHEET 2 FRANCIS J. FOX, OF PITTSBURGH, PENNSYLVANIA.

UN DERREAMER.

To all whom it may concern Be it known that I, FRANCIS J. Fox, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented. certain new and useful Improvements in Underreamers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to new and useful improvements in under reamers and the principal object of the invention is to provide a device for enlarging the-bore of a well beneath the casing to permit the casing to be sunk deeper.

Another object of the invention is to provide an under reamer which is so constructed as to be readily removed after the bore has been enlarged to the proper distance.

A further object of the invention isto pro vide a device which may be easily and cheaply manufactured and which may be readily inserted and removed from the well casing or pipe.

\Vith these and other objects in view, the invention consists in the novel combination and arrangement of parts which will be fully set forth in the following specification and accompanying drawings, in which Figure 1 is a fragmentary view of a well casing illustrating the under reameg being inserted therein. Fig. 2 is a sectional view through a well casing showing the under reamer being lowered into place and illustrating the under reamer in section. Fig. 3 is a longitudinal sectional view through the under reamer illustrating the same after it has been lowered below the lower end of the well casing and when it is in position for use. Fig. 4 is a transverse sectional view on line 1- 1 of Fig. 2. Fig. 5 is a transverse sectional view on line 55 of Fig 3. Fig. 6 is a transverse sectional view on line 6-6 of Fig. 3, and Fig. 7 is a perspective View of one of the cutters.

Referring to the drawings 1 designates as an entirety an under reamer constructed in accordance with this invention-consisting of a body 2 having in its upper end a longitudinally extending axial bore 3 which extends downwardly to a point substantially midway between the upper and lower terminals of the device. The'up-per end of the body 2 is provided with the reduced tapered Specification of Letters Patent.

threaded extension 4 which forms the connection between the drill rod and the under reamer. Extending upwardly from the lower end of the body 2 to a point slightly below the lower terminal of the bore 3 is an enlarged axial bore 5 having its inner end wall recessed as at 6 to accommodate the cutters which will be more fully hereinafter described. Formed at the lower terminal of the bore 5 and on the interior thereof are suitable screw threads which are adapted to cooperate with threads on the plug 7 for supporting said plug in place. Formed at diametrically opposite points in the upper end of the body 2 are suitable slots 8 the outer sides of which are enlarged as at 9 to form guide grooves in which the jaw controlling latches which will be more fully hereinafter described are slidable. The slots 8 extend downwardly to a point slightly above the lower terminal of the bore 3 and arranged in the body 2 near the upper end of the bore 5 are suitable slots 10 in which the cutters are slidable. The walls of these .slots inc-line as clearly shown in Fig. 6 to prevent the cutters from moving outwardly beyond a predetermined point. A reduced central bore 11 connects the bores 3 and 5 and is adapted to accommodate the cutter controlling rod which will be more fully hereinafter described.

Slidably mounted in the bore 11 is the operating rod 12 carrying at its upper end the cross head 13, the arms 14 of which are slidable in the slots 8. The lower terminal of the rod is threaded and provided with a nut 15 by means of which the wedge block 16 which is slidable thereon is adapted to be adjusted. Formed near the ends of the arms 14 are suitable longitudinal slots for the reception of the pins 17 which support the latch members designated by the numeral 18 in place. The upper ends of these latch members are provided with the curved portions 19 which are adapted to engage the Patented Aug. 1, 1916.

Application filed April 21, 1916. Serial No. 92,651.

well casing when the tool is being removed.

the grooves 9. In order to normally tend to force the cutters outwardly a suitable compression coil spring 22 surrounds the rod 12 and the lower end of said sprmg abuts the lower endwall of the bore 3 while the upper end of said spring engages the under side of the cross head 13. It will thus be seen that the wedge block 16 is normally urged upwardly into the position illustrated in Fig. 3.

The cutters above referred to are best illustrated in Fig. 7 and each comprises a body 23 having inclined side walls which conformto the inclination of the side walls of the groove 10 and the upper end of the body is formed with an inwardly offset portion 2-1 having an inner inclined face 25 against which the inclined faces of the wedge block 16 engage. The portion 24: extends upwardly .as clearly shown in the drawings and engages against the inner face of the upper end of bore 5 and when in position shown in Fig. 3 it will be evident that the upper'terminal of the extension 24 engages in a recess '6.

' In order to hold the cutters inwardly when the device is being inserted in a well casing, the ring designated by the numeral 26 is provided and it will be seen uponreference to Fig. 2 that when the device is to be slipped into the well casing the cross head is moved downwardly until the latches 18 aline with the recesses 21 and when in this position it will be seen that the latches will engage in said recesses and against the shoulders 20 thereby holding the wedge block 16 downwardly and out of engage ment with the cutters thus allowing the cutters to swing inwardly. In order that the latches 18 may be held against outward movement from position in the notches 21,

the ring 26 is slipped over the same and it will be apparent that the device may then be inserted in the well casing as illustrated in Fig. 1. Upon slipping the lower end of the under reamer into the upper end of the well casing and lowering the same it will be seen that the ring 26 will engage the upper edge of the casing and will gradually be pushed off of the under reamer so that the casing holds the latches in place and whenthe under reamer reaches its lower-limit of travel it will be evident that the latches will have passed below the lower terminal of the well casing and being free to move out wardly due to the inclination of the shoulders 20 it will be evident that they will move outwardly and upwardly thereby allowing theicros's head to move upwardly and draw the wedge block 16 into such a position as to expand the cutters. After the cutting operation has been completed the user then draws the tool upwardly until the upper ends 19 of the latches 18 engage the lower end of the well casing whereupon the latches will'be held substantially stationary while the body of-the tool moves upwardly until the latches come in alinement with the recesses 21 whereby due to the inclination of the upper ends 19 the latches will move inwardly into said recesses and thus lock the cross head and wedge block into their lowered position thus allowing the cutters to move inwardly and out of operative position. I

lVhile in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood dinal extremities of the body, the oppositev end of the body being provided with a relatively-large axial bore extending to a point below the lower terminal of the first mentioned'bore, the portion of the body between the bores being provided with an axial "aperture, a rod slidable through said aperture, a cross head at the upper end of the rod, a spring bearing on the under side of the cross head and on the bottom wall of the upper axial bore, the body being provided with a pair of diametrically disposed grooves having enlarged chambers formed at the lower terminal, the inner wall of each groove being slotted, said slots communicating with the'reduced bore, arms on the cross head slidable in the slots, said arms being provided with longitudinal slots near their outer ends, latch members mounted on the slotted ends of the arms and adapted to travel in the grooves, springs to normally urge the latch members outwardly, a wedge at the lower end of the rod and adjustably mounted tl1e1'e0n, the body being provided with slots near its lower terminal, said slots being radially arranged around the body and cutters operable in said slots, said cutters being provided with inclined inner faces for engagement with the wedge member.

2. An under reamer comprising a body-having an axial bore in its upper end extending to a point centrally of the longitudinal extremities of the body, the said body being provided with a bore in its lower end extending to a point slightly below the lower terminal of the upper bore, the material between the b'ores being provided with an axial aperture. a' rod slidable in said aperture, a cross head at the upper end of the rod a spring for engagement with the under side of the cross head and the bottom, wall of the upper bore to normally urge said cross head and rod upwardly, the body being provided with a pair-of diametrically opposed grooves near its upper end, the inner walls of the grooves being provided with longitudinally extending slots which communicate with the bore, the lower ends of the grooves terminating into chambers, latch members carried by the ends of the arms of the cross head and slidable in the grooves, said arms being slidable in the slots, a wedge member at the lower end of the rod and cutters operable through the body and controlled by the wedge member. 7

3. An under reamer comprising a body having an axial bore extending from its upper end to a point substantially centrally of its longitudinal extremities, the said body being also provided with a bore extending from its lower end to a point slightly below the lower end of" the upper bore, said bores being connected by an axial aperture, the upper endof the body being provided with a pair of diametrically opposed slots and having grooves extending the length of the slots and arranged in alinement therewith, the lower terminals of the grooves opening into chambers, a rod slidable through the axial opening, a cross head at the upper end of the rod, means to normally urge the cross head upwardly, latches carried by the cross head and adapted to engage the end walls of the chambers to hold the cross head downwardly, awedge'carried by the lower end of the rod and cutters adapted to be forced into'operative position by the wedge when the cross head moves upwardly.

4. An under reamer comprising a body, an-

axial bore extending into the body from its upper end, a second axial bore extending into the body from its lower end,- said bores terminating short of each' other, the body between the bores being provided with an axial aperture, the upper end of the body being provided with an elongated slot communicating with the bore and having grooves disposed in alinement with the slot,

the lower terminals of the grooves being env larged to form chambers, vshoulders formed by the upper end walls of the chambers, a rod slidable through the aperture connecting the bores, a cros head at the upper end of the rod, means to urge the cross head upwardly, latches carried by the ends of the arms of the cross head and slidable in the grooves, said latches being adapted to engage the shoulders formed by the chambers to hold the cross head downwardly against the influence of the upwardly urging means, cutters carried by the lower end of the body substantially T-shaped head at the upper end of the rod, the arms of said head projecting throughtheslots near the upper end of the body, latches slidably mounted on the ends of the arms and adapted to slide in the grooves, the said latches when the device is in its inoperative position resting in the recesses at the bottom of the grooves, cutters operable through the slots-near the bottom of the body and a wedge block carried by the rod for moving the cutters outwardly upon the upward movement of the rod and means a to normally tend to move said rod upwardly. v 6. An under reamer including .a hollow body having slots near its lower end, cutters mounted in the slots and adapted to project outwardly beyond the wall of the body when the device is in operative position, the body being provided with longitudinal grooves near its upper end and having slots extending inwardly from the grooves and communicating with the interior of the body, the bottom walls of the grooves being recessed near their lower ends, the upper walls of the recesses inclining upwardly and outwardly, a rod slidable longitudinally through the body, a substantially T-shaped head at the upper end of the rod, latches carried by the head and slidable in the grooves, the arms of said head projects ing through the slots near the upper end of the body, the upper ends of the latches being beveled to fit the inclination of the upper walls of the recesses, a spring to normally forcethe rod upwardly and a wedge supported on the lower end of the rod for engagement against the inner sides of the cutters to force said cutters outwardly when the rodmoves upwardly.

In testimony wliereof I aiiix my signature in presence of'two witnesses;

E. J. KENT. 

